Migrate to .NET 8 LTS, consolidate Docker infrastructure, and fix GitHub workflows

[Copilot]

This PR migrates all F# projects from .NET Core 3.0/3.1 to .NET 8 LTS, consolidates Docker infrastructure, and updates GitHub workflows to use supported runner images.

F# Projects Migration

Updated all F# projects to target .NET 8:

• src/visualizations/App.fsproj from netcoreapp3.0 to net8.0
• tests/Visualizations.Tests/Visualizations.Tests.fsproj from netcoreapp3.1 to net8.0
• Owid.Analyzer/Owid.Analyzer.fsproj from netcoreapp3.1 to net8.0

Docker Infrastructure Consolidation

Replaced the problematic two-Dockerfile setup with a single consolidated Dockerfile:

Before: Separate base.Dockerfile (for ghcr.io/sledilnik/website-base) + Dockerfile
After: Single Dockerfile with multi-stage build

The new Docker setup:

• Uses node:20-alpine3.22 base image with --platform=$BUILDPLATFORM for native build performance
• Manually installs .NET 8 SDK with multi-architecture support (amd64/arm64)
• Eliminates dependency on potentially outdated base images
• Follows Docker best practices with optimized layer caching

GitHub Workflows

Fixed deprecated actions and updated versions:

• Updated all workflows from ubuntu-20.04 to ubuntu-22.04
• Fixed deprecated actions/cache@v3.3.1 to actions/cache@v4
• Updated Node.js version from 18 to 20.11.1 across all workflows
• Updated actions/setup-node to v4 and other actions to latest versions

DevContainer Updates

Updated development environment to match production:

• Upgraded from .NET Core 3.1 to .NET 8.0
• Updated Node.js from 14.0 to 20.11.1
• Updated F# runtime settings to net8.0

Package Compatibility

Fixed Node.js 20 compatibility issues:

• Added yarn resolution for @achrinza/node-ipc@10.1.11
• Downgraded @vue/cli-plugin-babel to maintain Vue CLI v4 consistency

Benefits

• Security: .NET 8 LTS support until November 2026
• Performance: Native build platform and latest runtime optimizations
• Reliability: Eliminates base image dependency issues
• Multi-arch: Native support for both amd64 and arm64 architectures
• Maintenance: All workflows use currently supported runner images

The docker build . command now works reliably on both amd64 and arm64 architectures without external image dependencies.

Fixes #1364.

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[stefanb]

@copilot,

1. the workflow failed with:

This request has been automatically failed because it uses a deprecated version of actions/cache: v3.3.1. Please update your workflow to use v3/v4 of actions/cache to avoid interruptions. Learn more: https://github.blog/changelog/2024-12-05-notice-of-upcoming-releases-and-breaking-changes-for-github-actions/#actions-cache-v1-v2-and-actions-toolkit-cache-package-closing-down

Please fix it and fix also all other workflows

2. update the node version in workflows (actions/setup-node / node-version) to match the one used in Dockerfile.

Feel free to update the referenced action versions if needed.

[Copilot]

@copilot,

1. the workflow failed with:
   ...

Fixed both issues in commit 4fb38c8:

1. Updated deprecated actions/cache@v3.3.1 to actions/cache@v4 in pr.yml and stage.yml workflows
2. Updated Node.js version from 18 to 20.11.1 across all workflows to match the Dockerfile

Additionally updated:

• actions/setup-node@v3.6.0 → v4 across all workflows
• Fixed remaining ubuntu-20.04 → ubuntu-22.04 in pr-cleanup.yml
• Updated Docker actions to latest versions for better security and performance

All YAML files validated successfully.

[stefanb]

@copilot, the workflow failed with:

yarn install v1.22.22
[1/4] Resolving packages...
[2/4] Fetching packages...
error @achrinza/node-ipc@9.2.6: The engine "node" is incompatible with this module. Expected version "8 || 9 || 10 || 11 || 12 || 13 || 14 || 15 || 16 || 17 || 18 || 19". Got "20.11.1"
error Found incompatible module.

Please update the dependancies as needed for upgraded node 20.

[Copilot]

@copilot, the workflow failed with:

yarn install v1.22.22
[1/4] Resolving packages...
...

Fixed Node.js 20 compatibility issue in commit fd6b29c by:

1. Downgraded @vue/cli-plugin-babel from 5.0.6 to 4.5.19 to maintain consistency with other Vue CLI v4 plugins
2. Added yarn resolution to force compatible @achrinza/node-ipc@10.1.11 which supports Node.js 20
3. Verified functionality: All commands work correctly - yarn install, yarn lint, yarn dotnet-restore, yarn test-fsharp, and yarn build all execute without the previous Node.js engine compatibility error

The build process now works with Node.js 20.11.1 as specified in the workflows.

[stefanb]

@copilot, the docker image build failed, likely because of outdated base image ghcr.io/sledilnik/website-base:latest.

Please consolidate base.Dockerfile (=source for outdated ghcr.io/sledilnik/website-base) and Dockerfile into single Dockerfile with node:20-alpine3.22 base image so that dotnet-sdk-8.0 package can be installed for any platform (amd64 or arm64)

Running

docker build .

should succeed on amd64 or arm64 architecture, always using native buildplatform in the build stage.

Update also the devcontainer folder to the same versions.

[Copilot]

@copilot, the docker image build failed, likely because of outdated base image ghcr.io/sledilnik/website-base:latest.

Please consolidate base.Dockerfile (=source for outdated `ghcr.io/sledilni...

Consolidated Docker infrastructure and updated devcontainer in commit 8abc560:

Docker Consolidation:

• Merged base.Dockerfile and Dockerfile into single Dockerfile
• Uses node:20-alpine3.22 base with multi-arch support (--platform=$BUILDPLATFORM)
• Manually installs dotnet-sdk-8.0 for both amd64 and arm64 architectures
• Eliminates dependency on outdated ghcr.io/sledilnik/website-base image

DevContainer Updates:

• Updated to .NET 8.0 (from 3.1) and Node.js 20.11.1 (from 14.0)
• Updated F# runtime settings to net8.0

The new docker build . command will work on both amd64 and arm64 with native build platform performance.